This patent document relates to display screens, display device and systems.
Large display screens are desirable in various applications. Due to various limitations in screen technologies, instead of making a large display screen from a single display screen, multiple small display screens can be tiled in an array to form a large display screen. Examples for such display screens formed by smaller screens include a video wall where multiple TV sets are stacked in a two-dimensional array. When displaying a large image on the multiple tiled TV sets, each TV set is controlled to display a portion of the full image and different portions of the full images are displayed by different TV sets.
In a scanning-beam display system, one or more optical beams can be scanned over a screen to form images on the screen. The one or more scanning optical beams can be laser beams generated from lasers to provide sufficient optical power to achieve a desired display brightness on the screen. In some implementations of such a display system, the screen may be a passive screen that does not emit light and uses the light of the one or more scanning optical beams to form the images by reflecting, diffusing or scattering the light of the one or more scanning optical beams. In other implementations, the screen of such a display system may have light-emitting materials that absorb the light of the one or more scanning optical beams and emit new light that forms the images and the light of the one or more scanning optical beams is not directly used in forming the images seen by a viewer.
The beam scanning in various scanning-beam display systems can be achieved by, e.g., using one or more beam scanners. Some laser display systems use a polygon scanner with multiple reflective facets to provide horizontal scanning and a vertical scanning mirror such as a galvo-driven mirror to provide vertical scanning. In operation, one facet of the polygon scanner scans one horizontal line as the polygon scanner spins to change the orientation and position of the facet and the next facet scans the next horizontal line. The horizontal scanning and the vertical scanning are synchronized to each other to project images on the screen.